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Topic: Swapping a 700R 4 into a 67 (Read 19007 times)

i have been considering swapping a 700 R 4 Trans. into my 67. It will be bolted behind my original 327 engine now pushing 400 hp. I now have a "built" TH 350 in there, backed by a 4:11 Posi rear-end. Looking for a little better Gas mileage, and lower RPM's on the road. Many people have told me this would be a great combo. My question is; I just heard that I may have to do some modifying to the Trans Tunnel to get it to fit. Is this right??? I really don't like the idea of doing that.

A friend of mine put a 700R 4 in his 66 nova and it fit without doing any tunnel work, but it was a tight fit if I remember correctly. You might even have to have shorten your drive shaft and change the yoke on the. TMR

You could always drop a 2004R into it - you can build them to handle all the horse power you want, plus they are identical in dimensions to the TH350. Driveshafts slide right in with no mods - same length, same yoke. Gives you a lock up converter, overdrive and no real hassle to install. There is a visual drawback (not much of one), in that the bellhousing carries a dual bolt pattern - BOP and Chevy. Remember, though , that these were used behind Monte SS's and Grand Nationals back in the day - use the right HD parts and configure them correctly, and they'll hold up behind a lot of HP engines. You'll need to source the Chevy dipstick and tube to mate the bolt pattern to a Chevy block, otherwise the tube bolts to the BOP bolt pattern.

One more good thing - find a local junkyard that has a lot of late 80's GM vehicles, and you've got a better than average chance of finding good core trannies for like $25.00, like I did. Bought several of them. Or, a lot of trans builders offer them as built/ready to go performance trans for about the same money as a 700.

My good friend and GM engineer built a 200, and put it behind his '69 Firebird 400 BB convertible - no mods, 8000 miles on it since with no problems behind the 400. Great cruising rpm and gas mileage, too. Adjustable lock up controller for his converter as well - really slick. Started with a '87 Monte SS used trans, built from there -

Not sure if the tunnel is any different than a 72, but if it is, you will not need to modify the tunnel or change the cross member. I just completed this swap and love it. Running a ZZ4 with TPI injection. Around 375hp and a 3:73 rear delivering about 16mpg.

BEWARE! You may not be happy with a 700R4 The gear ratio spacing is not the best. First gear is very low compared to other options. The 700R4 shifts from 1st to 2nd and feels like it just shifted from 1st to 3rd. With a 3:73 rear gear I didn't like it at all. I pulled out the 700R4 and gave it away. Replaced it with an Autogear M22W 4speed.

You can change the ratios in a 700R4 or use one from a Corvette that has better ratio spacing.